Power supply for a mass analyzer

Abstract

A voltage supply (10) for a mass analyzer (1), comprising: a voltage source (16) having a first voltage output (12) configured to provide a first voltage to a first electrode (32) of the mass analyzer (1), wherein the first electrode (32) of the mass analyzer (1) has a first mass shift per volt perturbation; a second voltage output (14) configured to provide a second voltage to a second electrode (34) of the mass analyzer (1), wherein the second electrode (34) of the mass analyzer (1) has a second mass shift per volt perturbation, wherein the second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation;and a voltage divider network (20) connected to the voltage source (16), the first voltage output (12), and the second voltage output (14), the voltage divider network (20) comprising: a first resistor (22) configured to define the first voltage, the first resistor (22) having a first temperature coefficient; and a second resistor (24) configured to define the second voltage, the second resistor (24) having a second temperature coefficient, the second temperature coefficient being selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34);

Description

Area of ​​Revelation

[0001] The present disclosure relates to a mass analyzer. In particular, the present disclosure relates to a power supply for a mass analyzer. State of the art

[0002] Commercial high-resolution, accurate mass analyzers are typically required to measure mass to within a few ppm of the true value, and sub-ppm values ​​are highly advantageous. With external calibration, accurate mass measurement depends on the stability of the mV level of the high-voltage power supplies over the period from the time the calibration is performed. There are two main forms of power supply instability in such power supplies that can affect the accuracy of measurements performed with a mass analyzer: jitter and power supply drift. Jitter

[0003] Power supply jitter occurs due to instabilities in the power supply at or above the analyzer acquisition frequency. Time-of-flight analyzers operate between 10 Hz and 30,000 Hz, with ion flight times varying from tens of microseconds to milliseconds. Time-averaged spectra can reduce the impact of power supply instabilities at a frequency greater than the averaging rate. Such time-averaging techniques typically yield averaged spectra at 10–200 Hz. However, jitter at or below the averaging frequency is not compensated for by such techniques.

[0004] The resolution of averaged ToF (time-of-flight) spectra is also compromised when jitter is significant at frequencies equal to or below the averaging frequency. At very high frequencies (MHz+), the noise can be averaged over the time ions spend on individual elements of the analyzer, greatly reducing the impact on mass accuracy and resolution.

[0005] Power supply filtering is known to counteract some of the effects of power supply jitter. Active or passive low-pass filters are traditionally used to remove ripple at higher frequencies. Suppressing such instability generally comes at the expense of additional resistors and high-voltage capacitors, which impacts power supply, safety, or the implementation of features like polarity switching. Furthermore, such filters do not address any noise that may still be induced between the filter and the electrodes. Power supply drift

[0006] Power supplies also drift over time as a result of low-frequency noise sources and changes in local temperature. During warm-up, a power supply can drift by hundreds of ppm before reaching equilibrium, and can typically drift by dozens of ppm per degree change in the ambient temperature.

[0007] A well-known technique for counteracting the effects of temperature drift on a mass analyzer is to control the temperature of the entire instrument (which also benefits mass error caused by thermal expansion of the analyzer), the entire power supply, or the critical temperature of components. For example, "On the Accurate Understanding of Mass Measurement Accuracy in Q-TOF MS," Atsuhiko Toyama, White Paper, April 6, 2019, discloses a time-of-flight mass analyzer with improved flight tube temperature management. The flight tube incorporates a black nickel coating on the flight tube body to maximize heat dissipation.

[0008] Against this background, it is an object of this disclosure to provide an improved or at least commercially relevant alternative for the power supply or the mass analyzer. Brief description

[0009] According to a first aspect of the disclosure, a voltage supply for a mass analyzer is provided. The voltage supply comprises a voltage source, a first voltage output, a second voltage output, and a voltage divider network. The first voltage output is configured to provide a first voltage to a first electrode of the mass analyzer, wherein the first electrode of the mass analyzer has a first mass shift per volt perturbation. The second voltage output is configured to provide a second voltage to a second electrode of the mass analyzer, wherein the second electrode of the mass analyzer has a second mass shift per volt perturbation. The second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation. The voltage divider network is connected to the voltage source, the first voltage output, and the second voltage output.The voltage divider network includes a first resistor and a second resistor. The first resistor is configured to define the first voltage, wherein the first resistor has a first temperature coefficient. The second resistor is configured to define the second voltage, wherein the second resistor has a second temperature coefficient. The second temperature coefficient is selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode is compensated by a second mass displacement associated with the second electrode.

[0010] The power supply according to the first aspect supplies first and second voltages to first and second electrodes of a mass analyzer, respectively. Perturbations in the voltages applied to these electrodes can result in a shift in the mass of an ion detected by the mass analyzer. It will be appreciated that, depending on the geometry of the mass analyzer / electrode, the relationship between the mass shift and the voltage perturbation (i.e., the mass shift per volt perturbation) can be positive or negative. For the power supply of the first aspect, a change in the temperature of the power supply causes a change in the resistance values ​​of the first and second resistors in the voltage divider network. This, in turn, causes a change in the voltages output by the power supply and thus results in a shift in the mass detected by the mass analyzer.

[0011] The first and second resistors of the first aspect have specified temperature coefficients. The temperature coefficient of each selected resistor determines the amount of mass shift in the mass analyzer per degree Kelvin of temperature variation. According to the first aspect, the temperature coefficients are selected such that a first mass shift associated with the first electrode is compensated by an opposite second mass shift associated with the second electrode. That is, instead of simply selecting the first and second resistors with the lowest temperature coefficients to minimize resistance drift in the power supply, one or more resistors can be intentionally selected with a higher temperature coefficient such that the overall mass shift of the mass analyzer per degree Kelvin is reduced.

[0012] While the power supply of the first aspect is directed to a power supply with two voltage outputs, it is understood that in some embodiments, the power supply may include a plurality of voltage outputs. For example, the power supply may include at least three, four, or five voltage outputs for connection to a corresponding electrode of a mass analyzer. Since each electrode of the mass analyzer has an associated mass shift per volt perturbation relationship, the resistors of the voltage divider network can be selected with appropriate temperature coefficients to reduce the total mass shift per degree Kelvin of temperature variation according to the principle of the first aspect.

[0013] According to a second aspect of the disclosure, a voltage supply for a mass analyzer is provided. The voltage supply comprises a voltage source, a first voltage output, a second voltage output, and a voltage divider network. The first voltage output is configured to provide a first voltage to a first electrode of the mass analyzer, wherein the first electrode of the mass analyzer has a first mass shift per volt perturbation. The second voltage output is configured to provide a second voltage to a second electrode of the mass analyzer, wherein the second electrode of the mass analyzer has a second mass shift per volt perturbation. The second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation. The voltage divider network is connected to the voltage source, the first voltage output, and the second voltage output.The voltage divider network includes a first resistor and a second resistor. The first resistor is configured to define the first voltage, wherein the first resistor has a first aging coefficient. The second resistor is configured to define the second voltage, wherein the second resistor has a second aging coefficient. The second aging coefficient is selected based on the first and second mass displacement per volt perturbations and the first aging coefficient such that a first mass displacement associated with the first electrode is compensated by a second mass displacement associated with the second electrode.

[0014] The power supply of the second aspect may be constructed similarly to the power supply of the first aspect. Instead of selecting resistors based on a temperature coefficient, the resistors are selected based on an aging coefficient. That is, the power supply of the second aspect addresses the problem of variations in the resistance of resistors over time. For example, the resistance of a given resistor may vary (age) over a period of weeks at a stable temperature. Such aging variation may be independent of any temperature dependence. For example, in embodiments where the temperature of the power supply is carefully controlled to reduce power supply drift resulting from temperature variation, power supply drift due to resistor aging may still occur.The power supply of the second aspect addresses this problem by providing resistors whose aging coefficients are selected to reduce the effect of resistor aging on the mass displacement of the mass analyzer. It should be understood that the aging coefficients of the resistors can be selected according to a similar principle as described above for the first aspect.

[0015] It should be understood that in some embodiments, the power supply may select first and second resistors based on both temperature coefficients and aging coefficients. Thus, in some embodiments, a power supply may be provided that combines the first and second aspects. That is, in some embodiments, the first resistor has a first temperature coefficient and a first aging coefficient, and the second resistor has a second temperature coefficient and a second aging coefficient.The second temperature coefficient and the second aging coefficient can then be selected based on the first and second mass shift per volt perturbations, the first temperature coefficient, and the first aging coefficient such that a first mass shift associated with the first electrode is compensated by a second mass shift associated with the second electrode. Thus, the power supply can provide voltage outputs for a mass analyzer that reduces or eliminates mass shifts in response to both temperature variation and resistance aging.

[0016] In some embodiments, the first temperature coefficient of the first resistor differs from the second temperature coefficient of the second resistor. In some embodiments, the first aging coefficient of the first resistor differs from the second aging coefficient of the second resistor.

[0017] In some embodiments, the first temperature coefficient of the first resistor is no greater than 50 ppm / K. In some embodiments, the second temperature coefficient of the second resistor is greater than the first temperature coefficient. Thus, the first resistor is selected with a relatively low temperature coefficient to reduce the overall voltage variation per degree Kelvin for the first electrode, while the second resistor can be selected with an intentionally higher temperature coefficient to reduce or eliminate a mass shift per degree Kelvin for the mass analyzer.

[0018] In some embodiments, the first aging coefficient of the first resistor is no greater than 50 ppm / week. In some embodiments, the second aging coefficient of the second resistor is greater than the first aging coefficient. Thus, the first resistor with a relatively low aging coefficient is selected to reduce the total weekly voltage variation for the first electrode, while the second resistor with an intentionally higher aging coefficient can be selected to reduce or eliminate a weekly mass shift for the mass analyzer.

[0019] In some embodiments, the first electrode of the mass analyzer has a first mass shift per volt perturbation of at least 0.001 ppm / mV, and the second electrode of the mass analyzer has a second mass shift per volt perturbation of at least -0.001 ppm / mV. It will be appreciated that in many cases, the magnitude of the first and second mass shift per volt perturbations (i.e., the absolute values) will be different, such that the mass analyzer has a (resulting) total mass shift per volt perturbation (either positive or negative). The power supplies of the first and second aspects aim to reduce this total mass shift per volt perturbation toward zero.

[0020] In some embodiments, the first voltage output is a first DC voltage output and / or the second voltage output is a second DC voltage output. In some embodiments, the first and / or second voltage outputs may be DC bias voltages for respective electrodes, with an RF voltage superimposed on the respective DC bias voltages. In some embodiments, the first and second voltage outputs are used to define the amplitude of a respective RF voltage.

[0021] According to a third aspect of the disclosure, a mass analyzer is provided. The mass analyzer comprises an ion source, an ion detector, a first electrode, a second electrode, and a voltage supply. The ion source is configured to output ions along an ion trajectory. The ion detector is configured to detect ions along the ion trajectory. The first electrode is arranged along the ion trajectory, wherein the first electrode has a first mass shift per volt perturbation. The second electrode is arranged along the ion trajectory, wherein the second electrode has a second mass shift per volt perturbation, wherein the second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation. The voltage supply comprises a voltage source, a first voltage output, a second voltage output, and a voltage divider network.The first voltage output is configured to provide a first voltage to the first electrode. The second voltage output is configured to provide a second voltage to the second electrode. The voltage divider network is connected to the first voltage output, the second voltage output, and the voltage source. The voltage divider network includes a first resistor configured to define the first voltage, wherein the first resistor has a first temperature coefficient, and a second resistor. The second resistor is configured to define the second voltage, wherein the second resistor has a second temperature coefficient.The second temperature coefficient is selected based on the first and second mass shift per volt perturbations and the first temperature coefficient such that a first mass shift associated with the first electrode is compensated by a second mass shift associated with the second electrode.

[0022] Thus, the mass analyzer of the third aspect may include a power supply according to the first aspect of the disclosure.

[0023] According to a fourth aspect of the disclosure, a mass analyzer is provided. The mass analyzer comprises an ion source, an ion detector, a first electrode, a second electrode, and a voltage supply. The ion source is configured to output ions along an ion trajectory. The ion detector is configured to detect ions along the ion trajectory. The first electrode is arranged along the ion trajectory, the first electrode having a first mass shift per volt perturbation. The second electrode is arranged along the ion trajectory, the second electrode having a second mass shift per volt perturbation, the second mass shift per volt perturbation being opposite to the first mass shift per volt perturbation. The voltage supply comprises a voltage source, a first voltage output, a second voltage output, and a voltage divider network.The first voltage output is configured to provide a first voltage to the first electrode. The second voltage output is configured to provide a second voltage to the second electrode. The voltage divider network is connected to the first voltage output, the second voltage output, and the voltage source. The voltage divider network includes a first resistor configured to define the first voltage, wherein the first resistor has a first aging coefficient, and a second resistor. The second resistor is configured to define the second voltage, wherein the second resistor has a second aging coefficient.The second aging coefficient is selected based on the first and second mass shift per volt perturbations and the first temperature coefficient such that a first mass shift associated with the first electrode is compensated by a second mass shift associated with the second electrode.

[0024] Thus, the mass analyzer of the fourth aspect may include a power supply according to the second aspect of the disclosure.

[0025] It will be appreciated that in some embodiments, a mass analyzer may be provided with a voltage supply, wherein the first and second resistors are selected according to both the first and second aspects of the disclosure.

[0026] In some embodiments, the first temperature coefficient of the first resistor differs from the second temperature coefficient of the second resistor. In some embodiments, the first aging coefficient of the first resistor differs from the second aging coefficient of the second resistor.

[0027] In some embodiments, the mass analyzer further comprises a jitter compensation electrode arranged along the ion trajectory, the compensation electrode being connected to the voltage source. The jitter compensation electrode has a mass displacement per volt perturbation configured to compensate for a net mass displacement per volt perturbation of the first and second electrodes. Thus, the mass analyzer can be provided with an additional electrode to counteract the effect of any jitter in the voltage source. Such voltage jitter can be independent of fluctuations due to temperature and / or resistor aging. Thus, any disturbances in the voltage provided by the voltage source that may affect the voltage divider network are also reproduced on the jitter compensation electrode.Since the jitter compensation electrode has an associated mass displacement per volt that is opposite to the net mass displacement per volt of the first and second electrodes, the jitter compensation electrode compensates for the mass displacement imposed on the first and second electrodes by the voltage disturbance.

[0028] While the jitter compensation electrode described above is configured to compensate for a net mass shift of the first and second electrodes of the mass analyzer, it should be understood that in other embodiments, the jitter compensation electrode may be configured to compensate for a net mass shift of a plurality of electrodes of the mass analyzer. That is, the jitter compensation electrode may be configured to compensate for the net mass shift of at least the electrodes with the most significant mass shifts per volt perturbations. For example, the jitter compensation electrode may compensate for the at least 3 electrodes of the mass analyzer with the most significant (i.e., highest) mass shifts per volt perturbations. In some embodiments, the jitter compensation electrode may compensate for the at least: 5, 7, 10, 15, or 20 electrodes of the mass analyzer with the most significant (i.e.,highest) mass shift per volt disturbances.

[0029] The jitter compensation electrode may be an electrode located at a point along the ion trajectory. That is, the jitter compensation electrode may be provided at any point along the ion trajectory between the ion source and the ion detector. For example, the jitter compensation electrode may be located before the first and second electrodes, between the first and second electrodes, or after the first and second electrodes along the ion trajectory. In some embodiments, the jitter compensation electrode may interact with the ion trajectory multiple times. That is, ions traveling along the ion trajectory may pass through an electric field provided by the jitter compensation electrode multiple times while traveling between the ion source and the ion detector.For example, in a ToF mass analyzer (or a multiple reflection ToF), the jitter compensation electrode can be provided such that an electric field extending from the jitter compensation electrode intersects the ion trajectory multiple times.

[0030] In some embodiments, the jitter compensation electrode is connected to the voltage source in parallel with the voltage divider network. In some embodiments, the jitter compensation electrode is capacitively coupled to the voltage source. Thus, any disturbances in the voltage provided by the voltage source that may affect the voltage divider network are also reproduced on the jitter compensation electrode.

[0031] In some embodiments, the mass analyzer comprises a time-of-flight (ToF) mass analyzer, wherein the ion detector and the first and second electrodes are provided within the ToF mass analyzer. In some embodiments, the mass analyzer comprises an ion mirror comprising the first and second electrodes. For example, a ToF mass analyzer may be provided with one ion mirror. In some embodiments, the ToF mass analyzer may be provided with a pair of opposing ion mirrors. In some embodiments, the ToF mass analyzer may be a multi-reflection ToF mass analyzer comprising a pair of ion mirrors. In some embodiments, the jitter compensation electrode may be provided in addition to the pair of ion mirrors.

[0032] In some embodiments, the mass analyzer comprises a Fourier transform mass analyzer, for example an orbital trap mass analyzer or an electrostatic ion trap mass analyzer.

[0033] While the third and fourth aspects of the disclosure described above may include a jitter compensation electrode in addition to the voltage supply of the first and / or second aspects, it is understood that in some embodiments the jitter compensation electrode may be provided independently of the voltage supply described above.

[0034] Thus, according to a fifth aspect of the disclosure, a mass analyzer is provided. The mass analyzer comprises an ion source, an ion detector, a plurality of electrodes, a jitter compensation electrode, and a voltage source. The ion source is configured to output ions along an ion trajectory. The ion detector is configured to detect ions along the ion trajectory. The plurality of electrodes are arranged along the ion trajectory. Each electrode of the plurality of electrodes has an associated mass shift per volt perturbation. The jitter compensation electrode is arranged along the ion trajectory. The jitter compensation electrode and the plurality of electrodes are each connected to the voltage source. The jitter compensation electrode has a mass shift per volt perturbation configured to compensate for a net mass shift per volt perturbation of the plurality of electrodes.

[0035] Thus, according to the fifth aspect of the disclosure, a jitter compensation electrode can be provided to counteract the effects of voltage source jitter on the electrodes of a mass analyzer. In particular, the jitter compensation electrode can be provided to counteract the effect of voltage source jitter on the electrodes of a mass analyzer. That is, the plurality of electrodes to be jitter-compensated can each be provided as part of a mass analyzer. For example, the mass analyzer can comprise a ToF or Fourier transform mass analyzer.

[0036] The mass analyzer of the fifth aspect may include any of the features described above in relation to the first to fourth aspects of the disclosure. Short description of the characters

[0037] Embodiments of the present disclosure will now be explained, by way of example only, with reference to the accompanying figures, in which: • Fig. 1 shows a schematic diagram of a mass analyzer and a power supply according to a first embodiment of the disclosure; • Fig. 2 shows a schematic diagram of a mass analyzer according to a second embodiment of the disclosure; • Fig. Figure 3 shows a schematic diagram of a jitter compensation electrode; • Fig. 4 shows a schematic diagram of a mass analyzer according to a third embodiment of the disclosure; and • Fig. 5 shows a schematic diagram of a mass analyzer according to a fourth embodiment of the disclosure. Detailed description

[0038] According to a first embodiment of the disclosure, a mass analyzer 1 is provided. A schematic diagram of the mass analyzer 1 is shown in Fig. 1. As shown in Fig. 1, the mass analyzer 1 comprises a power supply 10 for the mass analyzer 1. As shown in Fig. 1, the power supply 10 includes a first voltage output 12, a second voltage output 14, a voltage source 16, and a voltage divider network 20. The mass analyzer 1 also includes an ion source 30, a first electrode 32, a second electrode 34, and an ion detector 36.

[0039] The Fig. The mass analyzer 1 shown schematically in Figure 1 is a time-of-flight (ToF) mass analyzer. While the description of the embodiment of the invention with respect to the embodiment of Fig.1, it will be understood that the invention may be applied to any mass spectrometer incorporating electrodes that may be subject to mass shifts resulting from power supply drift and / or jitter.

[0040] The mass analyzer from Fig. 1 contains an ion source 30. The ion source is configured to emit ions along an ion trajectory. The ion trajectory is shown in the schematic diagram of Fig. 1. The ion trajectory extends from the ion source 30 into a flight chamber 38 of the ToF. The first electrode 32 is arranged as an ion mirror in the flight chamber 38. The ion mirror is configured to reflect ions back to the entrance of the flight chamber 38, where an ion detector 36 is located. The principles of operating a ToF with one or more ion mirrors are known to those skilled in the art and are therefore not described in further detail herein.

[0041] The ion source 30 that outputs ions into the ToF can be any suitable ion source. For example, the ion source 30 can include an ion trap (not shown) that accumulates ions prior to their output into the ToF. The ion trap, in turn, can be connected to other ion-optical components of a mass spectrometer system configured to generate and transport ions to the ion trap. Alternatively, the ion source can be an electrospray ion source configured to generate and output ions to the ToF.

[0042] To reflect the ions migrating along the ion trajectory back to the ion detector 38, the first and second electrodes 32, 34 are connected to first and second voltage outputs 12, 14 of a power supply 10, respectively. The power supply is configured to output a first voltage (V1) to the first electrode 12 and a second voltage (V2) to the second electrode 14.

[0043] For the ToF mass analyzer from Fig.1, the mass of an ion is determined based on the time it takes the ion to travel from the ion source 30 to the ion detector 36. Higher mass ions take longer to transit from the ion source 30 to the ion detector 36 than lower mass ions. The time required depends on the mass of the ion as well as the magnitudes of the voltages applied to the first and second electrodes 32, 34. Generally, the voltages applied to the first and second electrodes 32, 34 are calibrated prior to an analysis such that they are known (and generally kept constant throughout an analysis). This, in turn, allows the mass of the ion to be inferred from the time of flight. It is therefore understood that unexpected changes in the voltages applied to the first and second electrodes 32, 34 may cause an unintended change in the ion's time of flight and, consequently, an error in the determined mass of the ion.

[0044] In the embodiment of Fig.1, the first electrode 32 acts as an ion mirror to reflect ions back to the entrance of the ToF. For positively charged ions, a positive first voltage V1 is applied to the first electrode 32. A positive perturbation of V1 has the effect of increasing the repulsion potential of the first electrode, effectively shortening the ion flight path for an ion of a given mass (i.e., reducing the time of flight for an ion). That is, a positive perturbation of the first voltage V1 results in a negative shift in the determined mass (relative to the mass that would be determined without the voltage perturbation). The amount of mass shift that occurs when the first voltage is perturbed can be calculated by mass analyzing an ion of known mass using the mass analyzer 1 under two different first voltages V1 and determining the resulting mass shift (as a percentage of the known mass of the ion).Based on the mass shift and the voltage difference, a relationship can be determined between the first voltage V1 applied to the first electrode and the resulting mass shift. That is, the first electrode 32 is associated with a first mass shift per volt perturbation Δ1 (i.e., the amount of mass shift caused by a 1 V perturbation in the voltage applied to the first electrode). For example, the first electrode 32 may have a first mass shift per volt perturbation Δ1 of -0.01 ppm / mV. In such a case, a voltage perturbation of +100 mV would cause a shift in the measured mass of an ion by -1 ppm (parts per million, i.e., 0.0001%). Accordingly, a voltage perturbation of -100 mV would cause a shift in the measured mass of an ion by +1 ppm.

[0045] In the embodiment of Fig.1, the second electrode 34 can be biased to increase the time of flight of ions through the mass analyzer. Thus, a positive voltage perturbation applied to the second electrode results in an increase in the mass of the ion measured by the ToF. That is, the second electrode is associated with a second mass shift per volt perturbation Δ2 that is opposite to that of the first electrode 32. The mass shift per volt perturbation characteristic for the second electrode 34 can be determined in a similar manner to that described above for the first electrode 32. For example, the second mass shift per volt perturbation characteristic associated with the second electrode Δ2 can be +0.01 ppm / mV. Thus, a voltage perturbation of 100 mV applied to the second electrode results in a shift of +1 ppm in the mass measured by the mass analyzer.

[0046] To apply the first and second voltages V1, V2 to the mass analyzer 1, a voltage supply 10 is provided. The voltage supply 10 includes a first voltage output 12 configured to provide the first voltage V1 to the first electrode 32. The voltage supply also includes a second voltage output 14 configured to provide the second voltage V2 to the second electrode 34. As discussed above, a first mass displacement per volt perturbation Δ1 is associated with the first electrode 32 and a second mass displacement per volt perturbation Δ2 is associated with the second electrode 34, wherein the second mass displacement per volt perturbation is opposite to the first mass displacement per volt perturbation (i.e., Δ1 has the opposite sign (positive or negative) to Δ2).

[0047] As in Fig.1, the power supply 10 comprises a voltage source 16. The voltage source 16 is a voltage source which, in combination with the voltage divider network, provides the desired voltage outputs to the first and second voltage outputs 12, 14. Thus, the voltage source 16 in the embodiment of Fig. 1 may be a DC voltage source, preferably for a DC voltage of more than 1000 V. Various circuits for providing a high voltage are known to those skilled in the art.

[0048] The voltage divider network 20 is connected to the voltage source 16, the first voltage output 12 and the second voltage output 14. The voltage divider network 20 is shown schematically in Fig.1. The voltage divider network 20 comprises a first resistor 22 and a second resistor 24. The first resistor 22 is configured to define the first voltage V1, which is output to the first voltage output 12. While in Fig. 1, the first voltage V1 is shown as being defined by a first resistor 22, it should be understood that in other embodiments, the first voltage V1 may be defined by one or more first resistors. Various voltage divider network circuits for providing a DC output of a desired voltage from a voltage source 16 are known to those skilled in the art and therefore will not be discussed in further detail herein.

[0049] Similar to the first resistor 22, the second resistor 24 is configured to define the second voltage V2. The second voltage V2 can also be defined by one or more second resistors 24.

[0050] The first and second resistors have a respective temperature coefficient (C1, C2). The temperature coefficient for each resistor represents how much the nominal resistance of the resistor changes with temperature. Conventionally, for applications where temperature stability is of utmost importance, resistors with a low temperature coefficient would normally be chosen (i.e., resistors where the change in resistance with temperature is relatively small). In embodiments of the present disclosure, the second temperature coefficient for the second resistor is selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode is compensated by a second mass displacement associated with the second electrode.This allows resistors with different temperature coefficients to be selected to compensate for the mass shift occurring in the mass analyzer.

[0051] For example, the first electrode 32 of the embodiment is supplied with a first voltage V1 of +6000 V, while the second electrode 34 is supplied with a second voltage V2 of +3000 V. The first electrode has a first associated mass shift per volt perturbation Δ1 of -0.01 ppm / mV. The second electrode has a second mass shift per volt perturbation Δ2 of +0.01 ppm / mV. In such an example, the first resistor 22 for defining the first voltage output 12 of the voltage divider network is selected with a first temperature coefficient C1 of 5 ppm / K (i.e., a resistance change of 0.0005% per degree Kelvin). A relatively low temperature coefficient is chosen for this resistor to minimize the overall temperature variations for the power supply 10.

[0052] Selecting such a first temperature coefficient results (approximately) in a variation of 30 mV in the first voltage V1 per degree Kelvin of temperature rise (i.e. δ v1 = C1 * V1). Consequently, the first electrode has an associated mass shift (δ m1 ) of δ m1 = Δ1 * δ V1 = -0.3 ppm / K.

[0053] The second resistor 22 is thus selected such that this mass shift is compensated (ie δ m2 = +0.3 ppm / K). That is, a second resistor is selected such that a voltage disturbance per degree Kelvin of δ V2 = δ m2 / Δ2 = 30 mV. For the second electrode 34, the ideal temperature coefficient for the corresponding second resistor is thus approximately C2 = δ V2 / V2 = 10 ppm / K. Thus, the selection of a second resistor with an intentionally higher temperature coefficient can actually provide a temperature compensation effect by accounting for the effect of a temperature-induced voltage perturbation on the resulting mass shift of the mass analyzer 1. Note that in the above example, it is assumed that a single resistor primarily defines the output voltage for each of the electrodes 32, 34, and thus the temperature coefficient of a single resistor is used in calculating the mass shift associated with each voltage output.

[0054] For other voltage divider networks, the relationship between the temperature coefficient of the resistor(s) and the voltage output of the voltage divider network may be different. For example, resistor dividers containing multiple resistors may use a combination of resistors with different thermal coefficients, which can be selected to provide more accurate compensation for mass shifts in the mass analyzer. Thus, the principle of selecting the temperature coefficients of one or more of the resistors to compensate for a mass shift in the mass analyzer can be applied to any suitable voltage supply for a mass analyzer 1.

[0055] The first and second resistors 22, 24 can be selected from resistors with temperature coefficients of, for example, 1 ppm / K, 2 ppm / K, 5 ppm / K, 10 ppm / K, 20 ppm / K, 50 ppm / K, 100 ppm / K, 200 ppm / K, 500 ppm / K, 1000 ppm / K, etc. In some embodiments, a resistor with the exact desired temperature coefficient may not be available; in this case, a second resistor (or a combination of the first and second resistors) with a temperature coefficient that minimizes the total (net) mass displacement may be selected.

[0056] While the above example is provided for the temperature coefficients C1, C2 of the first and second resistors 22, 24, respectively, it should be understood that a similar selection can also be made for aging coefficients (A1, A2) of resistors. An aging coefficient of a resistor reflects the resistance change of the resistor over time. Resistors can age due to repeated voltage cycling of the resistor or due to the passage of time. One way to characterize resistor aging is an aging coefficient expressed as parts per million resistance change per week (ppm / week), with the passage of time being the primary resistor aging mechanism. In such embodiments, the aging coefficients for the resistors can be selected to attempt to compensate for fluctuations in the mass displacement of the mass analyzer 1 over time. For example, for the mass analyzer of Fig. 1, with the parameters described above, a first resistor 22 with an aging coefficient A1 of 20 ppm / week could be selected. In such a case, a second resistor 24 with an aging coefficient of 40 ppm / week would compensate for the mass shift resulting from the aging of the first resistor.

[0057] It will also be appreciated that the first and second resistors for the first embodiment may be selected with respective aging coefficients and temperature coefficients such that the power supply 10 compensates for mass shifts resulting from both temperature variations and aging variations.

[0058] The Fig.While the first embodiment shown in Figure 1 is representative of a mass analyzer 1 with a first electrode 32 and a second electrode 34, other electrodes (or other voltage-controlled ion-optical devices) may be present, each with an associated mass shift per volt perturbation. Each of these electrodes / devices may be compensated using a voltage supply with appropriately selected resistors.

[0059] As another example, Fig. 2 is a schematic diagram of a mass analyzer 100 according to a second embodiment of the disclosure.

[0060] Similar to the first embodiment, the mass analyzer 100 is a time-of-flight mass analyzer. Similar components in Fig. 2 like the mass analyzer 1 of Fig. 1 share the same reference numerals. As in Fig.2, the mass analyzer 100 includes an ion source 30, an ion detector 36, a flight tube 38, and a power supply 10.

[0061] The Mass Analyzer 100 from Fig. 2 also includes a plurality of electrodes 33 (33a, 33b, 33c, 33d, 33e, 33f, 33g, 33h). The plurality of electrodes is similar to the first and second electrodes 32, 34 of Fig. 1, arranged as an ion mirror. Each of the plurality of electrodes 33 is associated with a mass shift per volt perturbation (Δ a , Δ b , Δ c , Δ d , Δ e , Δ f , Δ g , Δ h ), similar to the first and second electrodes 32, 34 of Fig.1. The plurality of electrodes 33 are each connected to a corresponding voltage output 13a, 13b, 13c, 13d, 13e, 13f, 13g, 13h of the voltage supply 10. The voltage supply 10 includes a voltage source 16 and a voltage divider network 20 to provide a DC voltage to each of the voltage outputs. In the embodiment of Fig. 2, voltage source 16 is an 8 kV DC voltage source. Each of the resistors in the voltage divider network can be selected with a temperature and / or aging coefficient to compensate for mass shifts resulting from temperature or aging variations.

[0062] As discussed above, it is understood that the mass displacement per volt perturbation of each of the plurality of electrodes 33 may be positive or negative. Likewise, the mass displacement per volt perturbation may be different for each of the electrodes. Consequently, the plurality of electrodes 33 may have a total (net) mass displacement per volt perturbation that is a sum of all individual mass displacement per volt perturbations for each of the electrodes (Δ netto = Δ a + Δ b + Δ c + Δ d + Δ e + Δ f + Δ g + Δ h). It is understood that the net mass shift per volt perturbation of the electrodes 33 cannot be zero. In such cases, a disturbance (jitter) at the voltage source 16 of the power supply 10 can cause a mass shift in the mass analyzer. Since all electrodes 33 are connected to the same voltage source 16, the voltage disturbance (jitter) affects all electrodes. Thus, the mass shift is proportional to the net mass shift per volt perturbation for the electrodes 33.

[0063] To counteract the effect of voltage source jitter, the mass analyzer 100 is Fig. 2 is provided with a jitter compensation electrode 40. The jitter compensation electrode 40 is arranged along the ion trajectory path. As shown in Fig.2, the jitter compensation electrode 40 is arranged between the flight tube 38 and the ion mirror. The jitter compensation electrode is provided such that it has an associated mass shift per volt perturbation that corresponds to the net mass shift per volt perturbation Δ netto of the electrodes 33. For example, in the embodiment of Fig. 2 a Δ netto of -0.1 ppm / mV. Accordingly, the jitter compensation electrode 40 is provided such that it has a mass shift per volt perturbation Δ Jitterof +0.1 ppm / mV. By connecting the jitter compensation electrode 40 to the voltage source 16, any voltage disturbances of the voltage source 16 are passed through the plurality of electrodes 33 and the jitter compensation electrode 40. Consequently, the mass shift of the plurality of electrodes 33 can be compensated by the mass shift of the jitter compensation electrode 40.

[0064] In the embodiment of Fig. 2, the jitter compensation electrode 40 is connected to the voltage source 16 in parallel with the voltage divider network 20. In the embodiment of Fig.2, the jitter compensation electrode 40 is capacitively coupled to the voltage source such that only voltage disturbances of a defined frequency range are reproduced on the jitter compensation electrode 40. In some embodiments, a coupling circuit 42 may be provided to capacitively couple the jitter compensation electrode 40 to the voltage source 16. In the embodiment of Fig.2, the coupling circuit 42 includes a resistor and a capacitor. Thus, the resistor and capacitor of the coupling circuit 42 can be selected to compensate for voltage source jitter with a frequency of at least, for example, 10 Hz. In some embodiments, the coupling circuit 42 can be configured to compensate for voltage source jitter with a frequency of no more than 30,000 Hz. In some embodiments, a coupling circuit 42 can be provided that only passes voltage supply jitter within a frequency range (i.e., a bandpass filter). Various bandpass filter circuits and other filter circuits for capacitive coupling are known to those skilled in the art and are therefore not discussed in further detail here.

[0065] In the mass analyzer of Fig.2, the most significant source of errors associated with voltage jitter relates to the voltage supply to the electrodes 33. As noted above, for the electrodes Δ netto = -0.1 ppm / mV. The sign of this perturbation arises because the stronger field shifts the reflection point outward toward the entrance to the ion mirror, effectively shortening the flight path. However, a positive voltage perturbation at the compensation electrode slows the passing ions, increases the flight time, and results in a mass shift of the same magnitude as the voltage perturbation.

[0066] By transferring voltage disturbances from the power supply to the jitter compensation electrode 40 via capacitive coupling, the time-of-flight disturbance is reduced. It is important that the length of the compensation electrode is adjusted relative to the flight tube such that the magnitude of the disturbance is similar to that of the ion mirror. This means that the length of the jitter compensation electrode along the ion trajectory can be adjusted / selected such that the desired Δ JitterAlternatively, the voltage jitter applied to the jitter compensation electrode 40 could be amplified or attenuated such that the resulting mass shift associated with the jitter compensation electrode compensates for the mass shift associated with the electrodes 33. In a relatively typical system with a short flight tube of <1 m, the compensation electrode portion of the flight tube could extend along a substantial portion of the flight tube. For example, the jitter compensation electrode may extend along at least: 50%, 70%, 80%, 90%, 95%, or 99% of the flight tube.

[0067] It should be noted that while the embodiment of Fig.2 uses capacitive coupling, other means for transmitting interference to a compensation electrode may also be suitable, for example, inductive coupling. Advantageously, inductive coupling eliminates the need for capacitors (e.g., relatively large nF-level HS capacitors), which can be used in capacitively coupled embodiments.

[0068] Thus, a mass analyzer 100 may be provided with a jitter compensation electrode 40 to compensate for power supply jitter. It should be understood that the jitter compensation electrode may be provided independently of the power supply 10. That is, in some embodiments, a mass analyzer 100 may be provided with a jitter compensation electrode and a conventional power supply.

[0069] While the jitter compensation electrode 40 of Fig.2 is capacitively coupled to the power supply 10, it is understood that in some embodiments of the disclosure, a jitter compensation electrode may be directly connected to a power supply, for example, a high-voltage power supply, which supplies high voltages (e.g., above 100 V) to one or more electrodes of the mass analyzer. An example of such a jitter compensation electrode is shown in Fig. 3 shown.

[0070] While a jitter compensation electrode comprising a single plate electrode could be directly connected to a high-voltage supply, such a jitter compensation electrode could complicate the overall design of the mass analyzer. In particular, ion trajectories that a jitter compensation electrode creates at the DC voltage of the power source (e.g., V HS in the embodiment of Fig.1) adversely affect the ion trajectory. This means that without careful design, the output potential of such a jitter compensation electrode may be too high for ions to pass the ion trajectory. Fig. The jitter compensation electrode shown in Figure 3 aims to reduce voltage penetration into the ion flight path by alternating high-voltage electrodes and grounded electrodes. Advantageously, a jitter compensation electrode directly connected to the high-voltage supply can be configured to compensate for both power supply drift and power supply temperature drift.

[0071] Thus, as in Fig.3, the jitter compensation electrode is a jitter compensation electrode assembly 50. The jitter compensation electrode assembly comprises a plurality of ring electrodes 51a, 51b, 51c, 51d, 51e, 51f, 51g, 51h, 51i, 51j, 51k arranged around the ion trajectory. The plurality of ring electrodes are alternately connected along the ion trajectory to either a voltage source or ground, with the voltage source connected to some of the plurality of ring electrodes being the voltage source to be jitter compensated. Thus, the jitter compensation electrode assembly 50 can be formed from a stacked ring ion guide with suitable alternating connections to either the voltage source or ground.

[0072] According to such a design for a jitter compensation electrode arrangement 50, the potential reaching the center of the jitter compensation electrode arrangement 50 is approximately half the voltage of the voltage source (V HS / 2 in Fig. 3). The voltage from the voltage source (V HS ) is alternately applied by electrodes at V HS and grounded electrodes along the ion trajectory are damped. The voltage experienced by ions in the center of the jitter-compensating electrode assembly 50 can be further damped, for example, by varying the thickness, pitch, or voltage application to the plates in the stack. The use of such a stacked ring ion guide as the jitter-compensating electrode assembly 50 can not only compensate for voltage supply jitter, but can also be provided to improve ion focusing in the mass analyzer.

[0073] Another alternative jitter compensation electrode (not shown) could be formed using a cylindrical mesh surrounding the ion trajectory, with the voltage (V HS ), which is to be jitter compensated, is applied to the cylindrical grid and surrounded by the flying potential from the ion source in such a way that the voltage in the center results in a superposition of the two.

[0074] The embodiments of Fig. 1 and Fig. 2 relate to the ToF mass analyzer 1, 100 with a single reflection ion trajectory. The principles of this disclosure can also be applied to multiple reflection ToF (MR-ToF) mass analyzers, such as in Fig. 4 shown.

[0075] Fig.Figure 4 shows a schematic diagram of an MR-ToF 200 according to a third embodiment of the disclosure. The MR-ToF 200 includes a first converging ion mirror 202 and a second converging ion mirror 204. The first and second converging ion mirrors 202, 204 are arranged opposite each other to define an ion trajectory involving multiple reflections between the first and second converging ion mirrors 202, 204. As further described in Fig. As shown in Figure 4, ions are input from an ion trap source 230 into the MR-ToF 200. The ions travel from the ion trap source 230 through a first out-of-plane lens 231, a first deflector 232, a second out-of-plane lens 233, and a second deflector 234 before traveling between the converging ion mirrors 202, 204. Ions exiting the MR-ToF 200 are captured by an ion detector 236.

[0076] In Fig.4, the first converging ion mirror 202 comprises five mirror electrodes 205, 206, 207, 208, 209. Each of the five mirror electrodes 205, 206, 207, 208, 209 has an associated mass shift per volt perturbation (Δ m1 , Δ m2 , Δ m3 , Δ m4 , Δ m5 ). The second converging ion mirror 204 may be provided with five mirror electrodes of a similar structure.

[0077] As in Fig. 4, the first and second converging ion mirrors 202, 204 are each connected to a voltage supply 210. The voltage supply 210 is Fig.4 is shown schematically as being connected to the first mirror electrode 205 of the first converging ion mirror 202. It is understood that the voltage supply 210 is connected to each of the mirror electrodes 205, 206, 207, 208, 209 to supply a desired DC voltage to each of the mirror electrodes. It is understood that the mirror electrodes of the second converging ion mirror 204 are also each connected to a voltage supply (in Fig. 4 not shown), which may be the same power supply 210 or a different power supply.

[0078] As in Fig. 4, a jitter compensation electrode 240 may be provided to compensate for the effects of power supply jitter. In the embodiment of Fig.4, a pair of jitter compensation electrodes 240 are provided, one for each of the first and second converging ion mirrors 202, 204. The jitter compensation electrodes 240 are disposed between the first and second converging ion mirrors 202, 204. The jitter compensation electrodes 240 are disposed adjacent to a respective converging ion mirror 202, 204. Each jitter compensation electrode 240 is configured to compensate for a net mass shift per volt perturbation associated with a respective converging ion mirror. Various configurations for suitable jitter compensation electrodes 240 will be apparent to those skilled in the art based on the embodiments of this disclosure. For example, the jitter compensation electrodes 240 may be provided in a similar manner to the correction strip electrodes, as further described in US 9,136,101 B2. In the embodiment of Fig.4, the jitter compensation electrodes are supplied with voltage for a jitter compensation voltage source 211. The jitter compensation electrodes are capacitively coupled to the voltage supply 210 via a capacitor.

[0079] As shown in Table 1 below, the five mirror electrodes of the first converging ion mirror are supplied with the following voltages (V) and have the following associated mass shift per volt perturbations (Δ). The voltage (V) and associated mass shift per volt perturbations (Δ) for the jitter compensation electrode are also shown in Table 1. Table 1 electrode Absolute voltage (V) Mass shift per volt perturbation (ppm / mV) First mirror electrode 205 +6000 -0,0935 Second mirror electrode 206 +3650 -0,0800 Third mirror electrode 207 +4600 +0,00704 Fourth mirror electrode 208 -7350 +0,0235 Fifth mirror electrode 209 0 0,0 Jitter compensation electrode 240 -23 +0,0935

[0080] As shown in Table 1, the mass displacement per volt perturbations associated with the mirror electrodes 205 and 206 are the most significant. The net mass displacement per volt perturbation (Δ netto) for the five mirror electrodes of the first ion mirror 202 is -0.143 ppm / mV. The jitter compensation electrode 240 can be provided with an associated mass shift per volt perturbation that compensates for at least a portion of the total net mass shift. Thus, by providing the mass analyzer 200 with the jitter compensation electrode 240, the net mass shift per volt perturbation is reduced to -0.0494 ppm / mV. Effectively, the jitter compensation electrode 240 compensates for any mass shift associated with voltage perturbations at the mirror electrode 205. Thus, as in Fig. As shown in Figure 4, the jitter compensation electrode 240 is capacitively coupled to the mirror electrode 205 via a capacitor. A similar capacitive coupling is used for the other jitter compensation electrode 240 and the second converging ion mirror 204 (not shown).

[0081] In addition to the jitter compensation, the MR-TOF 200 can also be provided with a voltage supply 210 configured to reduce the power supply drift (temperature drift and / or aging drift) for the mirror electrodes 205, 206, 207, 208, 209 of the converging ion mirrors 202, 204.

[0082] Similar to the embodiments described above, the voltages supplied to the four mirror electrodes receiving a non-zero voltage 205, 206, 207, 208 can be defined using a voltage divider network (not shown). In such a voltage divider network, the one or more resistors defining a corresponding voltage for each of the four mirror electrodes 205, 206, 207, 208 can be selected to reduce and / or eliminate the net effect of temperature drift and / or aging.

[0083] For example, as shown in Table 2 below, resistors with a temperature coefficient of 5 ppm / K can be selected for the voltage divider network for outputting voltages for the first, second, and fourth mirror electrodes 205, 206, 208. As shown in Table 2 below, a temperature drift of +1 K would produce a net mass shift of -3.4 ppm in the MR-ToF 200. If the resistor(s) of the voltage divider network for outputting the voltage for the third mirror electrode 207 were selected with temperature coefficients of 100 ppm / K, the temperature mass drift of +1 K would produce a mass shift associated with the third electrode 207 of +3.24 ppm. Thus, the temperature coefficients for the resistors of the voltage divider network can be selected such that the net temperature drift of the mass analyzer 200 is reduced to -0.26 ppm / K.Thus, by intentionally using one or more resistors with a higher temperature coefficient than other resistors in the voltage divider network, the mass analyzer 200 can be provided with a temperature drift of less than + / - 1 ppm / K. Table 2 electrode Absolute voltage, V(V) Mass shift per volt perturbation, Δ(ppm / mV) Temperature coefficient,C(ppm / K) Voltage disturbance per degree Kelvin,δv(mV / K) Mass shift per degree Kelvin (ppm / K) First mirror electrode 205 +6000 -0,0935 5 30 -2,81 Second mirror electrode 206 +3650 -0,0800 5 18,25 -1,46 Third mirror electrode 207 +4600 +0,00704 100 460 +3,24 Fourth mirror electrode 208 -7350 +0,0235 5 36,75 +0,863

[0084] While the above table refers to the resistances of the power supply 210 for the converging ion mirrors 202, 204, it should be understood that the principle of resistance selection can also be applied to the power supply for any other component of the mass analyzer 200, where a voltage disturbance can result in a mass shift in the detected mass of an ion. For example, the same principle can be applied to the power supply for one or more of the following: a voltage of the ion trap source 230, the first out-of-plane lens 231, the first deflector 232, the second out-of-plane lens 233, and the second deflector 234.

[0085] While the above discussion of Fig.4 refers to the selection of resistors with a desired temperature coefficient, it will be understood that the same principles can also be applied to the selection of resistors with a desired aging coefficient in order to reduce or eliminate the effect of age-related drift on the mass analyzer 200.

[0086] While the embodiments of Fig. 1, Fig. 2 and Fig. 4 refer to ToF mass analyzers, it should be understood that the present disclosure is not limited to ToF mass analyzers. For example, embodiments of the disclosure include power supplies for other types of mass analyzers, such as ion trap mass analyzers or Fourier transform mass analyzers.

[0087] According to a fourth embodiment, Fig.5 is a schematic diagram of a Fourier transform mass analyzer. The Fourier transform mass analyzer of Fig. 5 is an orbital trap mass analyzer 300. The orbital trap mass analyzer can be provided, for example, as substantially described in US Pat. No. 8,841,604 B2. The orbital trap mass analyzer 300 includes an inner electrode 302 and a plurality of outer sheath electrodes 504. A voltage supply 310 is connected to the inner electrode 302, while the outer electrodes 304 are used to detect the ion current orbiting the inner electrodes. As shown in Fig. 5, a jitter compensation electrode 340 could be provided adjacent to one or more of the outer electrodes 304. For example, as shown in Fig.5, the jitter compensation electrode may be provided in a slot provided in one of the outer electrodes 304. The jitter compensation electrode 540 may be directly or capacitively coupled to the power supply 310, wherein the jitter compensation electrode is configured to compensate for voltage jitter at the inner electrode 302. In some embodiments, the power supply may also be configured to include a voltage divider network (not shown) to provide voltages to the inner electrode 302 and the jitter compensation electrode 340. In such an embodiment, the voltage divider network may include resistors selected to reduce thermal drift and / or aging drift of the power supply 310 according to the embodiments described above.

[0088] Thus, according to embodiments of the disclosure, the mass shift associated with voltages applied to components (e.g., electrodes) of a mass analyzer can be used to configure the mass analyzer to reduce or eliminate the effects of power supply requirements and / or power supply jitter. Such principles can be used to provide a mass analyzer with high stability (e.g., thermal stability of less than 1 ppm / K), such that a highly accurate measurement can be performed using the mass analyzer. In particular, a power supply for a mass analyzer can be provided according to the embodiments described above.

Claims

[1] A voltage supply (10) for a mass analyzer (1), comprising: a voltage source (16) having a first voltage output (12) configured to provide a first voltage to a first electrode (32) of the mass analyzer (1), wherein the first electrode (32) of the mass analyzer (1) has a first mass shift per volt perturbation; a second voltage output (14) configured to provide a second voltage to a second electrode (34) of the mass analyzer (1), wherein the second electrode (34) of the mass analyzer (1) has a second mass shift per volt perturbation, wherein the second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation;and a voltage divider network (20) connected to the voltage source (16), the first voltage output (12), and the second voltage output (14), the voltage divider network (20) comprising: a first resistor (22) configured to define the first voltage, the first resistor (22) having a first temperature coefficient; and a second resistor (24) configured to define the second voltage, the second resistor (24) having a second temperature coefficient, the second temperature coefficient being selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34); [2] A voltage supply (10) for a mass analyzer (1), comprising a voltage source (16); a first voltage output (12) configured to provide a first voltage to a first electrode (32) of the mass analyzer (1), wherein the first electrode (32) of the mass analyzer (1) has a first mass shift per volt perturbation; a second voltage output (14) configured to provide a second voltage to a second electrode (34) of the mass analyzer (1), wherein the second electrode (34) of the mass analyzer (1) has a second mass shift per volt perturbation, wherein the second mass shift per volt perturbation is opposite to the first mass shift per volt perturbation;and a voltage divider network (20) connected to the first voltage output (12), the second voltage output (14), and the voltage source (16), the voltage divider network (20) comprising: a first resistor (22) configured to define the first voltage, the first resistor (22) having a first aging coefficient; and a second resistor (24) configured to define the second voltage, the second resistor (24) having a second aging coefficient, the second aging coefficient being selected based on the first and second mass displacement per volt perturbations and the first aging coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34); [3] A power supply (10) according to claim 1, wherein the first temperature coefficient of the first resistor (22) differs from the second temperature coefficient of the second resistor (24); or a power supply (10) according to claim 2, wherein the first aging coefficient of the first resistor (22) differs from the second aging coefficient of the second resistor (24). [4] The power supply (10) of any preceding claim, wherein the first resistor (22) has a first temperature coefficient and a first aging coefficient, and the second resistor (24) has a second temperature coefficient and a second aging coefficient, wherein the second temperature coefficient and the second aging coefficient are selected based on the first and second mass displacement per volt perturbations, the first temperature coefficient, and the first aging coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34). [5] Power supply (10) according to one of the preceding claims, wherein the first temperature coefficient of the first resistor (22) is not greater than 50 ppm / K or the first aging coefficient of the first resistor (22) is not greater than 50 ppm / week. [6] A power supply (10) according to any preceding claim, wherein the first electrode (32) of the mass analyzer (1) has a first mass shift per volt perturbation of at least 0.001 ppm / mV; and the second electrode (34) of the mass analyzer (1) has a second mass shift per volt perturbation of at least -0.001 ppm / mV. [7] Power supply (10) according to one of the preceding claims, wherein the first voltage output (12) is a first DC voltage output; and / or the second voltage output (14) is a second DC voltage output. [8] A mass analyzer (1) comprising: an ion source (30) configured to output ions along an ion trajectory; an ion detector (36) configured to detect ions along the ion trajectory; a first electrode (32) disposed along the ion trajectory, the first electrode (32) having a first mass shift per volt perturbation; a second electrode (34) disposed along the ion trajectory, the second electrode (34) having a second mass shift per volt perturbation, the second mass shift per volt perturbation being opposite to the first mass shift per volt perturbation; and a voltage supply (10) comprising: a voltage source (16); a first voltage output (12) configured to provide a first voltage to the first electrode (32);a second voltage output (14) configured to provide a second voltage to the second electrode (34); and a voltage divider network (20) connected to the first voltage output (12), the second voltage output (14), and the voltage source (16), the voltage divider network (20) comprising: a first resistor (22) configured to define the first voltage, the first resistor (22) having a first temperature coefficient;and a second resistor (24) configured to define the second voltage, the second resistor (24) having a second temperature coefficient, the second temperature coefficient being selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34); [9] A mass analyzer (1) comprising: an ion source (30) configured to output ions along an ion trajectory; an ion detector (36) configured to detect ions along the ion trajectory; a first electrode (32) arranged along the ion trajectory, the first electrode (32) having a first mass shift per volt perturbation; a second electrode (34) arranged along the ion trajectory, the second electrode (34) having a second mass shift per volt perturbation, the second mass shift per volt perturbation being opposite to the first mass shift per volt perturbation; and a voltage supply (10) comprising: a voltage source (16) having a first voltage output (12) configured to provide a first voltage to the first electrode (32);a second voltage output (14) configured to provide a second voltage to the second electrode (34); and a voltage divider network (20) connected to the first voltage output (12), the second voltage output (14), and the voltage source (16), the voltage divider network (20) comprising: a first resistor (22) configured to define the first voltage, the first resistor (22) having a first aging coefficient;and a second resistor (24) configured to define the second voltage, the second resistor (24) having a second aging coefficient, the second aging coefficient being selected based on the first and second mass displacement per volt perturbations and the first temperature coefficient such that a first mass displacement associated with the first electrode (32) is compensated by a second mass displacement associated with the second electrode (34); [10] A mass analyzer (1) according to claim 8, wherein the first temperature coefficient of the first resistor (22) differs from the second temperature coefficient of the second resistor (24); or a power supply (10) according to claim 9, wherein the first aging coefficient of the first resistor (22) differs from the second aging coefficient of the second resistor (24). [11] A mass analyzer (1) according to any one of claims 8 to 10, further comprising a jitter compensation electrode (40) arranged along the ion trajectory, the jitter compensation electrode (40) being connected to the voltage source (16); the jitter compensation electrode (40) having a mass displacement per volt perturbation configured to compensate for a net mass displacement per volt perturbation of the first (32) and second electrodes (34). [12] Mass analyzer (1) according to claim 11, wherein the jitter compensation electrode (40) is connected to the voltage source (16) in parallel with the voltage divider network (20). [13] A mass analyzer (1) according to any one of claims 8 to 12, wherein the mass analyzer (1) comprises a time-of-flight (ToF) mass analyzer, the ion detector (36) and the first (32) and second electrodes (34) being provided within the ToF mass analyzer. [14] Mass analyzer (1) according to one of claims 8 to 13, wherein the mass analyzer (1) comprises an ion mirror comprising the first electrode (32) and the second electrode (34). [15] Mass analyzer (1) according to one of claims 8 to 12, wherein the mass analyzer (1) comprises an orbital trap mass analyzer (300).

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